A favorite garden vegetable of many is the tomato. It is fairly easy to grow in a garden, and smaller varieties can be grown in containers. Containing vitamins A, C and iron, plus low in calories, many might say the tomato is even terrific, but a Purdue expert said it was not always so popular.
The tomato is native to South America, and introduced by early explorers into Europe where it became known as the “Apple of Love” in France and Italy. “It was not generally cultivated in the United States until 1835 because, until then, it was widely believed to be poisonous,” said Rosie Lerner, consumer horticulture specialist at Purdue University in her publication entitled, “Tomatoes.”
“Tomatoes are available in a wide variety of shapes, sizes and colors,” she said. “While red tomatoes are the most common, yellow, orange and pink tomatoes are sometimes grown.” Shapes can be round, flattened or pear-shaped. “Sizes range from bite-size cherry types to the giant beefsteak tomatoes,” she said.
Most tomatoes can be used fresh for eating and cooking, but paste or Roma type tomatoes are best suited for cooking down to sauces or used for ketchup.
Selection of a favorite tomato variety is a lifelong pursuit for some avid gardeners. There are new varieties each year to choose from and experiment with.
“Tomatoes will grow in many different soil types, but a deep, loamy, well-drained soil is ideal,” said Lerner. “Tomatoes grow best in a slightly acid soil with a pH of 6.2-6.8.”
Tomatoes are typically transplanted into the garden rather than direct-seeded. Choose short, stocky plants with a thick stem and dark green color. Transplanting should always take place after danger of frost is past. Tomatoes should be in full sun, or a minimum of 6 hours of direct sunlight per day. Do not plant near walnut trees.
Tomatoes are classified as determinate (bush-type), indeterminate or dwarf. Determinate tomatoes grow to a certain height, then flower and fruit at a more “determinate” time than spread out all season long, like indeterminate tomatoes. Smaller in stature, determinate and dwarf tomatoes are better suited for containers, while indeterminate tomatoes are normally grown in a garden setting, preferably with stakes and cages.
“Tomatoes need 1-1.5 inches of water per week to maintain plant health and good quality fruit,” Lerner said. “Applying a mulch will help conserve soil moisture by preventing evaporation and will help prevent extremes in the moisture supply.”
Tomatoes can be picked “vine-ripe” at peak of freshness and maturity. They can also be picked a little early and allowed to fully ripen off the plant. This may be particularly helpful as danger of frost nears, or to better avoid sunscald and skin cracking during the growing season.
When canning, some have feared that low-acid tomatoes could cause botulism poisoning. “The acidity of a tomato does vary depending on location in the garden and degree of ripeness,” Lerner said. “However, the low-acid tomatoes are just as acidic as other tomatoes.” She said that low-acid tomatoes just have a higher sugar content, which makes them taste less acidic.
Have you ever pondered the age-old question, “Is the tomato a fruit or a vegetable?” Botanically, the ovary of any flowering plant that contains seed is the fruit — whether it is dry or fleshy. However, as we think of foods, the tomato is not sweet, like many traditional fruits. The term “vegetable” is used in European and American cuisine — generally as salad ingredients, part of the main meal, or as a side-dish with a main meal. An 1887 U.S. tariff law imposed a tax on imported vegetables, but not fruit, and importers argued that since it was a fruit, no tax was due. The U.S. Supreme Court eventually settled the issue, ruling in 1893 that in the United States, the tomato is a vegetable.
For more information about growing tomatoes, access Lerner’s publication at edustore.purdue.edu. Additionally, find a wealth of information about using tomatoes and other vegetables at Purdue Extension’s FoodLink, extension.purdue.edu/foodlink.